An optoelectronic device such as a photovoltaic cell, a light emitting diode (LED), an organic light emitting diode (OLED), or the like may include an encapsulant that encapsulates a light emission or light sensing site of the device.
For example, a solar cell module may be typically manufactured by laminating a transparent front substrate which is a light-receiving substrate, an encapsulant, a photovoltaic element, an encapsulant, and a back sheet, and then thermally compressing the laminate while subjecting the laminate to vacuum suction.
As an encapsulant used in the solar cell module, an ethylene-vinyl acetate (EVA) resin is most commonly used in terms of processability, constructability, cost, and the like.
However, the EVA resin has low adhesion strength to a front substrate or back sheet, and thus, when a module is exposed to the outdoors for a long time, there is a problem in that delamination or peeling between layers easily occurs. Also, in the process of manufacturing a solar cell module using an encapsulant including an EVA resin, the EVA resin is thermally decomposed according to heat compression conditions, and thus acetic acid gas and the like may be generated. The above-described acetic acid gas has problems in that the gas aggravates the working environment, adversely affects a photovoltaic element, an electrode, or the like included in the solar cell module, and causes deterioration in the module, decrease in electricity generation efficiency, and the like.
Therefore, there is a continued need for an encapsulant for an optoelectronic device having improved long-term adhesion characteristics.